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Articles 61 - 90 of 94

Full-Text Articles in Medical Biochemistry

Copper Triflate-Mediated Synthesis Of 1,3,5-Triarylpyrazoles In [Bmim][Pf6] Ionic Liquid And Evaluation Of Their Anticancer Activities, V. Kameshwara Rao, Rakesh Tiwari, Bhupender S. Chhikara, Amir Nasrolahi Shirazi, Keykavous Parang, Anil Kumar Jan 2013

Copper Triflate-Mediated Synthesis Of 1,3,5-Triarylpyrazoles In [Bmim][Pf6] Ionic Liquid And Evaluation Of Their Anticancer Activities, V. Kameshwara Rao, Rakesh Tiwari, Bhupender S. Chhikara, Amir Nasrolahi Shirazi, Keykavous Parang, Anil Kumar

Pharmacy Faculty Articles and Research

A simple, efficient, and environment friendly protocol for the synthesis of 1,3,5-triarylpyrazoles and 1,3,5-triarylpyrazolines in [bmim][PF6] ionic liquid mediated by Cu(OTf)2 is described. The reaction protocol gave 1,3,5-triarylpyrazoles in good to high yields (71–84%) via a one-pot addition–cyclocondensation between chalcones and arylhydrazines, and oxidative aromatization without the requirement for an additional oxidizing reagent. The catalyst can be reused for up to four cycles without much loss in the catalytic activity. The pyrazoles (4a–o) and pyrazolines (3a–n) were evaluated for their antiproliferative activity in SK-OV-3, HT-29, and HeLa human cancer cells lines. Among all the compounds, 3b inhibited cell proliferation of …


Synthetic Peptides Derived From The Sequence Of A Lasso Peptide Microcin J25 Show Antibacterial Activity, Rania Soudy, Liru Wang, Kamaljit Kaur Jan 2012

Synthetic Peptides Derived From The Sequence Of A Lasso Peptide Microcin J25 Show Antibacterial Activity, Rania Soudy, Liru Wang, Kamaljit Kaur

Pharmacy Faculty Articles and Research

Microcin J25 (MccJ25) is a plasmid-encoded, ribosomally synthesized antibacterial peptide with a unique lasso structure. The lasso structure, produced with the aid of two processing enzymes, provides exceptional stability to MccJ25. We report the synthesis of six peptides (1–6), derived from the MccJ25 sequence, that are designed to form folded conformation by disulfide bond formation and electrostatic or hydrophobic interactions. Two peptides (1 and 6) display good activity against Salmonella newport, and are the first synthetic derivatives of MccJ25 that are bactericidal. Peptide 1 displays potent activity against several Salmonella strains including two …


Synthesis And Anti–Hiv Activities Of Symmetrical Dicarboxylate Esters Of Dinucleoside Reverse Transcriptase Inhibitors, Hitesh K. Agarwal, Karen W. Buckheit, Robert W. Buckheit Jr., Keykavous Parang Jan 2012

Synthesis And Anti–Hiv Activities Of Symmetrical Dicarboxylate Esters Of Dinucleoside Reverse Transcriptase Inhibitors, Hitesh K. Agarwal, Karen W. Buckheit, Robert W. Buckheit Jr., Keykavous Parang

Pharmacy Faculty Articles and Research

Three nucleoside analogues, 3′-fluoro-2′,3′-dideoxythymidine (FLT), 3′-azido-2′,3′-dideoxythymidine (AZT), and 2′,3′-dideoxy-3′-thiacytidine (3TC) were conjugated with three different dicarboxylic acids to afford the long chain dicarboxylate esters of nucleosides. In general, dinucleoside ester conjugates of FLT and 3TC with long chain dicarboxylic acids exhibited higher anti-HIV activity than their parent nucleosides. Dodecanoate and tetradecanoate dinucleoside ester derivatives of FLT were found to be the most potent compounds with EC50 values of 0.8–1.0 nM and 3–4 nM against HIV-1US/92/727 and HIV-1IIIB cells, respectively. The anti-HIV activity of the 3TC conjugates containing long chain dicarboxylate diester (EC50 = 3–60 nM) was improved by 1.5–66 fold …


One-Pot Regioselective Synthesis Of Tetrahydroindazolones And Evaluation Of Their Anti-Proliferative And Src Kinase Inhibitory Activities, V. Kameshwara Rao, Bhupender S. Chhikara, Rakesh Tiwari, Amir Nasrolahi Shirazi, Keykavous Parang, Anil Kumar Jan 2012

One-Pot Regioselective Synthesis Of Tetrahydroindazolones And Evaluation Of Their Anti-Proliferative And Src Kinase Inhibitory Activities, V. Kameshwara Rao, Bhupender S. Chhikara, Rakesh Tiwari, Amir Nasrolahi Shirazi, Keykavous Parang, Anil Kumar

Pharmacy Faculty Articles and Research

A number of 2-substituted tetrahydroindazolones were synthesized by three-component condensation reaction of 1,3- diketones, substituted hydrazines, benzaldehydes, and Yb(OTf)3 as a catalyst in [bmim][BF4] ionic liquid using a simple, efficient, and economical one-pot method. The synthesized tetrahydroindazolones were evaluated for inhibition of cell proliferation of human colon carcinoma (HT-29), human ovarian adenocarcinoma (SK-OV-3), and c-Src kinase activity. 3,4-Dichlorophenyl tetrahydroindazolone derivative (15) inhibited the cell proliferation of HT-29 and SK-OV-3 cells by 62% and 58%, respectively. 2,3-Diphenylsubstituted tetrahydroindazolone derivatives, 19, 25, and 33, inhibited the cell proliferation of HT-29 cells by 6572% at a concentration of 50 μM. In general, the …


3-Substitued Indoles: One Pot Synthesis And Evaluation Of Anticancer And Src Kinase Inhibitory Activities, V. Kameshwara Rao, Bhupender S. Chhikara, Amir Nasrolahi Shirazi, Rakesh Tiwari, Keykavous Parang, Anil Kumar Jan 2011

3-Substitued Indoles: One Pot Synthesis And Evaluation Of Anticancer And Src Kinase Inhibitory Activities, V. Kameshwara Rao, Bhupender S. Chhikara, Amir Nasrolahi Shirazi, Rakesh Tiwari, Keykavous Parang, Anil Kumar

Pharmacy Faculty Articles and Research

An efficient and economical method was developed for the synthesis of 3-substituted indoles by one pot three-component coupling reaction of a substituted or unsubstituted benzaldehyde, N-methylaniline, and indole or N-methylindole using Yb(OTf)3-SiO2 as a catalyst. All the synthesized compounds were evaluated for inhibition of cell proliferation of human colon carcinoma (HT-29), human ovarian adenocarcinoma (SK-OV-3), and c-Src kinase activity. The 4-methylphenyl (4o and 4p) and 4-methoxyphenyl (4q) indole derivatives inhibited the cell proliferation of SK-OV-3 and HT-29 cells by 7077% at a concentration of 50 μM. The unsubstituted phenyl (4d) and 3-nitrophenyl (4l) derivatives showed the inhibition of c-Src kinase …


Click Chemistry Inspired One-Pot Synthesis Of 1, 4-Disubstituted 1, 2, 3-Triazoles And Their Src Kinase Inhibitory Activity, Dalip Kumar, V. Buchi Reddy, Anil Kumar, Deendayal Mandal, Rakesh Tiwari, Keykavous Parang Jan 2011

Click Chemistry Inspired One-Pot Synthesis Of 1, 4-Disubstituted 1, 2, 3-Triazoles And Their Src Kinase Inhibitory Activity, Dalip Kumar, V. Buchi Reddy, Anil Kumar, Deendayal Mandal, Rakesh Tiwari, Keykavous Parang

Pharmacy Faculty Articles and Research

Two classes of 1,4-disubstituted 1,2,3-triazoles were synthesized using one-pot reaction of α-tosyloxy ketones/α-halo ketones, sodium azide, and terminal alkynes in the presence of aq. PEG (1:1, v/v) using the click chemistry approach and evaluated for Src kinase inhibitory activity. Structure-activity relationship analysis demonstrated that insertion of C6H5- and 4-CH3C6H4- at position 4 for both classes and less bulkier aromatic group at position 1 in class 1 contribute critically to the modest Src inhibition activity (IC50 = 32-43 µM) of 1,4-disubstituted 1,2,3-triazoles.


Inhibition Of Multi-Drug Resistant Hiv-1 Reverse Transcriptase By Nucleoside Beta-Triphosphates, Chandravanu Dash, Yousef Ahmadibeni, Michael J. Hanley, Jui Pandhare, Mathias Gotte, Stuart F. J. Le Grice, Keykavous Parang Jan 2011

Inhibition Of Multi-Drug Resistant Hiv-1 Reverse Transcriptase By Nucleoside Beta-Triphosphates, Chandravanu Dash, Yousef Ahmadibeni, Michael J. Hanley, Jui Pandhare, Mathias Gotte, Stuart F. J. Le Grice, Keykavous Parang

Pharmacy Faculty Articles and Research

Despite the success of potent reverse transcriptase (RT) inhibitors against human immunodeficiency virus type 1 (HIV-1) in combination regimens, the development of drug resistant RTs constitutes a major hurdle for the long-term efficacy of current antiretroviral therapy. Nucleoside β-triphosphate analogs of adenosine and nucleoside reverse transcriptase inhibitors (NRTIs) (3′-azido-2′,3′-dideoxythymidine (AZT), 3′-fluoro-2′,3′-dideoxythymidine (FLT), and 2′,3′-didehydro-2′,3′-dideoxythymidine (d4T)) were synthesized and their inhibitory activities were evaluated against wild-type and multidrug resistant HIV-1 RTs. Adenosine β-triphosphate (1) and AZT β-triphosphate (2) completely inhibited the DNA polymerase activity of wild type, the NRTI multi resistant, and nonnucleoside RT inhibitors (NNRTI) resistant HIV-1 RT at 10 …


Thiazolyl N-Benzyl-Substituted Acetamide Derivatives: Synthesis, Src Kinase Inhibitory And Anticancer Activities, Asal Fallah-Tafti, Alireza Foroumadi, Rakesh Tiwari, Amir Nasrolahi Shirazi, David G. Hangauer, Yahao Bu, Tahmineh Akbarzadeh, Keykavous Parang, Abbas Shafiee Jan 2011

Thiazolyl N-Benzyl-Substituted Acetamide Derivatives: Synthesis, Src Kinase Inhibitory And Anticancer Activities, Asal Fallah-Tafti, Alireza Foroumadi, Rakesh Tiwari, Amir Nasrolahi Shirazi, David G. Hangauer, Yahao Bu, Tahmineh Akbarzadeh, Keykavous Parang, Abbas Shafiee

Pharmacy Faculty Articles and Research

KX2-391 (KX-01/Kinex Pharmaceuticals), N-benzyl-2-(5-(4-(2-morpholinoethoxy)phenyl)pyridin-2-yl)acetamide, is a highly selective Src substrate binding site inhibitor. To understand better the role of pyridine ring and N-benzylsubstitution in KX2-391 and establish the structure-activity relationship, a number of N-benzyl substituted (2-morpholinoethoxy)phenyl)thiazol-4-yl)acetamide derivatives containing thiazole instead of pyridine were synthesized and evaluated for Src kinase inhibitory activities. The unsubstituted N-benzyl derivative (8a) showed the inhibition of c-Src kinase with GI50 values of 1.34 μM and 2.30 M in NIH3T3/c-Src527F and SYF/c-Src527F cells, respectively. All the synthesized compounds were evaluated for inhibition of cell proliferation of human colon carcinoma (HT-29), breast carcinoma (BT-20), and leukemia (CCRF-CEM) cells. …


Synthesis Of 3-Phenylpyrazolopyrimidine-1,2,3-Triazole Conjugates And Evaluation Of Their Src Kinase Inhibitory And Anticancer Activities, Anil Kumar, Israr Ahmad, Bhupender S. Chhikara, Rakesh Tiwari, Deendayal Mandal, Keykavous Parang Jan 2011

Synthesis Of 3-Phenylpyrazolopyrimidine-1,2,3-Triazole Conjugates And Evaluation Of Their Src Kinase Inhibitory And Anticancer Activities, Anil Kumar, Israr Ahmad, Bhupender S. Chhikara, Rakesh Tiwari, Deendayal Mandal, Keykavous Parang

Pharmacy Faculty Articles and Research

A series of two classes of 3-phenylpyrazolopyrimidine-1,2,3-triazole conjugates were synthesized using click chemistry approach. All compounds were evaluated for inhibition of Src kinase and human ovarian adenocarcinoma (SK-Ov-3), breast carcinoma (MDA-MB-361), and colon adenocarcinoma (HT-29). Hexyl triazolyl-substituted 3-phenylpyrazolopyrimidine exhibited inhibition of Src kinase with an IC50 value of 5.6 µM. 4-Methoxyphenyl triazolyl-substituted 3-phenylpyrazolopyrimidine inhibited the cell proliferation of HT-29 and SK-Ov-3 by 73% and 58%, respectively, at a concentration of 50 µM.


Nanosized Hydroxyapatite And Other Calcium Phosphates: Chemistry Of Formation And Application As Drug And Gene Delivery Agents, Vuk Uskoković, Dragan Uskoković Nov 2010

Nanosized Hydroxyapatite And Other Calcium Phosphates: Chemistry Of Formation And Application As Drug And Gene Delivery Agents, Vuk Uskoković, Dragan Uskoković

Pharmacy Faculty Articles and Research

The first part of this review looks at the fundamental properties of hydroxyapatite (HAP), the basic mineral constituent of mammalian hard tissues, including the physicochemical features that govern its formation by precipitation. A special emphasis is placed on the analysis of qualities of different methods of synthesis and of the phase transformations intrinsic to the formation of HAP following precipitation from aqueous solutions. This serves as an introduction to the second part and the main subject of this review, which relates to the discourse regarding the prospects of fabrication of ultrafine, nanosized particles based on calcium phosphate carriers with various …


Morphological Study Of Emulsion-Assisted Cholesterol Precipitation Processes, Vuk Uskoković Sep 2010

Morphological Study Of Emulsion-Assisted Cholesterol Precipitation Processes, Vuk Uskoković

Pharmacy Faculty Articles and Research

Crystallization of cholesterol in chemical conditions that involve the presence of emulsions of three different types of surface active agents—cationic, anionic, and nonionic—was investigated by means of scanning and transmission electron microscopic analyses. In contrast with the previous attempts to modify the typical plate- and needle-shaped character of biaxially grown cholesterol crystals, the present study indicates that spherical templates of fine emulsion droplets may impose spherical morphologies to cholesterol particles nucleated within.


Chronic Inflammatory Responses To Microgel-Based Implant Coatings, Amanda W. Bridges, Rachel E. Whitmire, Neetu Singh, Kellie L. Templeman, Julia E. Babensee, L. Andrew Lyon, Andrés J. García Jan 2010

Chronic Inflammatory Responses To Microgel-Based Implant Coatings, Amanda W. Bridges, Rachel E. Whitmire, Neetu Singh, Kellie L. Templeman, Julia E. Babensee, L. Andrew Lyon, Andrés J. García

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Inflammatory responses to implanted biomedical devices elicit a foreign body fibrotic reaction that limits device integration and performance in various biomedical applications. We examined chronic inflammatory responses to microgel conformal coatings consisting of thin films of poly(N-isopropylacrylamide) hydrogel microparticles cross-linked with poly(ethylene glycol) diacrylate deposited on poly(ethylene terephthalate) (PET). Unmodified and microgel-coated PET disks were implanted subcutaneously in rats for 4 weeks and explants were analyzed by histology and immunohistochemistry. Microgel coatings reduced chronic inflammation and resulted in a more mature/organized fibrous capsule. Microgel-coated samples exhibited 22% thinner fibrous capsules that contained 40% fewer cells compared to unmodified PET disks. …


5¢-O-B,G-Methylenetriphosphate Derivatives Of Nucleoside, Yousef Ahmadibeni, Chandravanu Dash, S. F. J. Le Grice, Keykavous Parang Jan 2010

5¢-O-B,G-Methylenetriphosphate Derivatives Of Nucleoside, Yousef Ahmadibeni, Chandravanu Dash, S. F. J. Le Grice, Keykavous Parang

Pharmacy Faculty Articles and Research

The solid-phase synthesis of 5¢-O-b,g-methylenetriphosphates of nucleosides 1–5 is described, where a 4-acetoxy-3-arylbenzyloxy group was used as a linker.


Synthesis And Evaluation Of Conformationally Constrained Peptide Analogues As The Src Sh3 Domain Binding Ligands, Rakesh Tiwari, Alex Brown, Seetha Narramaneni, Gongqin Sun, Keykavous Parang Jan 2010

Synthesis And Evaluation Of Conformationally Constrained Peptide Analogues As The Src Sh3 Domain Binding Ligands, Rakesh Tiwari, Alex Brown, Seetha Narramaneni, Gongqin Sun, Keykavous Parang

Pharmacy Faculty Articles and Research

Src kinase activity is regulated by the interaction of SH3 domain with protein sequences that are rich in proline residues. Identification of more potent SH3 domain binding ligands that can regulate Src kinase activity is a subject of major interest. Conformationally constrained peptides have been previously used for improving the binding potency of the Src SH2 domain binding peptide ligands and peptide substrates of the substrate-binding site of Src. A series of peptide analogues of Ac-VSLARRPLPPLP (1, Ac-VSL-12, Kd = 0.34 M) were synthesized by introducing conformational constraints to improve the binding affinity towards the Src SH3 domain. Peptides synthesized …


Prospects And Pits On The Path Of Biomimetics: The Case Of Tooth Enamel, Vuk Uskoković Jan 2010

Prospects And Pits On The Path Of Biomimetics: The Case Of Tooth Enamel, Vuk Uskoković

Pharmacy Faculty Articles and Research

This review presents a discourse on challenges in understanding and imitating the process of amelogenesis in vitro on the molecular scale. In light of the analysis of imitation of the growth of dental enamel, it also impends on the prospects and potential drawbacks of the biomimetic approach in general. As the formation of enamel proceeds with the protein matrix guiding the crystal growth, while at the same time conducting its own degradation and removal, it is argued that three aspects of amelogenesis need to be induced in parallel: a) crystal growth; b) protein assembly; c) proteolytic degradation. A particular emphasis …


Synthesis, Antiviral And Contraceptive Activities Of Nucleoside-Sodium Cellulose Sulfate Acetate And Succinate Conjugates, Hitesh K. Agarwal, Anil Kumar, Gustavo F. Doncel, Keykavous Parang Jan 2010

Synthesis, Antiviral And Contraceptive Activities Of Nucleoside-Sodium Cellulose Sulfate Acetate And Succinate Conjugates, Hitesh K. Agarwal, Anil Kumar, Gustavo F. Doncel, Keykavous Parang

Pharmacy Faculty Articles and Research

Chemical conjugates between sodium cellulose sulfate (CS), displaying contraceptive and HIV-entry inhibiting properties, and nucleoside reverse transcriptase inhibitors (NRTIs) (3′-azido-2′,3′-dideoxythymidine (AZT), 3′-fluoro-2′,3′-dideoxythymidine (FLT), or 2',3'-dideoxy-3'-thiacytidine (3TC)) were designed to simultaneously provide contraceptive and anti-HIV activity. Two linkers, acetate and succinate, were used to conjugate the nucleoside analogs with CS. The conjugates containing cellulose sulfate-acetate (CSA) (e.g., AZT-CSA and FLT-CSA) were found to be more potent than CS and other conjugates (e.g., AZT-succinate-CS, and FLT-succinate-CS). The presence of both sulfate and the acetate groups on cellulose were critical for generating maximum anti-HIV activity. In addition to showing equal potency against wild-type …


The Proteolytic Stability And Cytotoxicity Studies Of L‐Aspartic Acid And L‐Diaminopropionic Acid Derived Β‐Peptides And A Mixed Α/Β‐Peptide, Sahar Ahmed, Kamaljit Kaur Apr 2009

The Proteolytic Stability And Cytotoxicity Studies Of L‐Aspartic Acid And L‐Diaminopropionic Acid Derived Β‐Peptides And A Mixed Α/Β‐Peptide, Sahar Ahmed, Kamaljit Kaur

Pharmacy Faculty Articles and Research

The use of peptides as drugs in pharmaceutical applications is hindered by their susceptibility to proteolysis and therefore low bioavailability. β‐Peptides that contain an additional methylene group in the backbone, are gaining recognition from a pharmaceutical stand point as they are considerably more resilient to proteolysis and metabolism. Recently, we reported two new classes of β‐peptides, β3‐ and β2‐peptides derived from l‐aspartic acid and l‐diaminopropionic acid, respectively. Here, we report the proteolytic stability of these β‐peptidic compounds and a mixed α /β‐peptide against three enzymes (pronase, trypsin and elastase), as well as, human serum. The …


Liquid Chromatography-Tandem Mass Spectrometry For The Determination Of Methylprednisolone In Rat Plasma And Liver After Intravenous Administration Of Its Liver-Targeted Dextran Prodrug, Shuang-Qing Zhang, Helen R. Thorsheim, Suman Penugonda, Venkateswaran C. Pillai, Quentin R. Smith, Reza Mehvar Jan 2009

Liquid Chromatography-Tandem Mass Spectrometry For The Determination Of Methylprednisolone In Rat Plasma And Liver After Intravenous Administration Of Its Liver-Targeted Dextran Prodrug, Shuang-Qing Zhang, Helen R. Thorsheim, Suman Penugonda, Venkateswaran C. Pillai, Quentin R. Smith, Reza Mehvar

Pharmacy Faculty Articles and Research

A specific and sensitive liquid chromatography (LC)-tandem mass spectrometric method for quantitative determination of methylprednisolone (MP) in rat plasma and liver was developed and validated using triamcinolone acetonide as an internal standard. Liquid-liquid extraction using tert-butyl methyl ether was used to extract the drug and the internal standard from plasma and liver. The separation of MP was performed on a C(18) column with a mobile phase of acetonitrile:0.5% formic acid aqueous solution (85:15, v/v) over 4 min. The assay was based on the selected reaction monitoring transitions at m/z 375 -> 161 for MP in plasma, 375 -> 357 for …


Surface Charge Effects Involved In The Control Of Stability Of Sols Comprising Uniform Cholesterol Particles, Vuk Uskoković Jul 2008

Surface Charge Effects Involved In The Control Of Stability Of Sols Comprising Uniform Cholesterol Particles, Vuk Uskoković

Pharmacy Faculty Articles and Research

The reported is a method for the preparation of stable dispersions of narrowly dispersed cholesterol crystals, which may provide an excellent model for the aggregation studies thereof. The effects of experimental parameters that include concentration, pH, ionic strength, temperature, and aging on the resulting morphologies are acknowledged. Regardless of the cause of destabilization, the multilayered aggregates of cholesterol particles are formed by “face-to-face” stacking of the original platelets, as promoted by higher surface charge density on particle sides comparing to their faces. In accordance with the crucial involvement of surface charge effects in stabilization of cholesterol dispersions produced hereby, aggregation …


Insights Into Morphological Nature Of Precipitation Of Cholesterol, Vuk Uskoković Mar 2008

Insights Into Morphological Nature Of Precipitation Of Cholesterol, Vuk Uskoković

Pharmacy Faculty Articles and Research

Additional effects on the previously reported procedure of precipitation of narrowly dispersed and well-defined, brick-shaped cholesterol particles, including non-solvent addition rate, temperature, solvent purity, aging treatments, ultrasound agitation and fine mechanical effects were investigated. Based on the presented results, significant morphological sensitivity of cholesterol precipitation processes upon variations from the standard established procedure of crystallization is induced. However, the tendency of cholesterol to crystallize in the form of biaxially grown particles was evidenced as dominating the precipitation processes, irrespective of any modifications of experimental parameters involved in the preparation procedure investigated hereby. Prolonged aging time and temperature effects lead to …


Composites Comprising Cholesterol And Carboxymethyl Cellulose, Vuk Uskoković Feb 2008

Composites Comprising Cholesterol And Carboxymethyl Cellulose, Vuk Uskoković

Pharmacy Faculty Articles and Research

Whereby cholesterol presents one of the major fatty substances in human body, carboxymethyl cellulose is a water-soluble derivative of cellulose, the most abundant dietary fiber. Whereas on one hand in vivo precipitation of cholesterol is the major cause of atherosclerosis, dietary fibers are on the other hand known for their ability to clean the fatty plaque deposited on intestinal pathways, and prevent its build-up in other critical areas within the organism. In this work, a method for the preparation of a composite material comprising cholesterol and carboxymethyl cellulose from 1-hexanol/water biphase mixtures is reported. Specificity of the interaction between the …


Right-Handed 14-Helix In Β3-Peptides From L-Aspartic Acid Monomers, Kamaljit Kaur, Tara Sprules, Wael Soliman, Reem Beleid, Sahar Ahmed Jan 2008

Right-Handed 14-Helix In Β3-Peptides From L-Aspartic Acid Monomers, Kamaljit Kaur, Tara Sprules, Wael Soliman, Reem Beleid, Sahar Ahmed

Pharmacy Faculty Articles and Research

β-Peptides made from L-aspartic acid monomers form a new class of β3-peptides. Here we report the first three-dimensional NMR solution structure of a β3-hexapeptide (1) from L-aspartic acid monomers in 2,2,2-trifluoroethanol (TFE). We show that 1 forms a right-handed 14-helical structure in TFE. α-peptides from naturally occurring L-amino acids adopt a right-handed α-helix whereas β3-peptides formed from β3-amino acids derived from naturally occurring L-amino acids form left-handed 14-helices. The right-handed 14-helical conformation of 1 is a better mimic of α-peptide conformations. Using the NMR structure of 1 in TFE, we …


Enzymatic Processing Of Amelogenin During Continuous Crystallization Of Apatite, Vuk Uskoković, M.-K. Kim, W. Li, S. Habelitz Jan 2008

Enzymatic Processing Of Amelogenin During Continuous Crystallization Of Apatite, Vuk Uskoković, M.-K. Kim, W. Li, S. Habelitz

Pharmacy Faculty Articles and Research

Dental enamel forms through a protein-controlled mineralization and enzymatic degradation with a nanoscale precision that new engineering technologies may be able to mimic. Recombinant fulllength human amelogenin (rH174) and a matrix-metalloprotease (MMP-20) were employed in a pHstat titration system that enabled a continuous supply of calcium and phosphate ions over several days, mimicking the initial stages of matrix processing and crystallization in enamel in-vitro. Effects on the self-assembly and crystal growth from a saturated aqueous solution containing 0.4 mg/ml rH174 and MMP-20 with the weight ratio of 1:1000 with respect to rH174 were investigated. A transition from nanospheres to fibrous …


Reduced Acute Inflammatory Responses To Microgel Conformal Coatings, Amanda W. Bridges, Neetu Singh, Kellie L. Burns, Julia E. Babensee, L. Andrew Lyon, Andrés J. García Jan 2008

Reduced Acute Inflammatory Responses To Microgel Conformal Coatings, Amanda W. Bridges, Neetu Singh, Kellie L. Burns, Julia E. Babensee, L. Andrew Lyon, Andrés J. García

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Implantation of synthetic materials into the body elicits inflammatory host responses that limit medical device integration and biological performance. This inflammatory cascade involves protein adsorption, leukocyte recruitment and activation, cytokine release, and fibrous encapsulation of the implant. We present a coating strategy based on thin films of poly(N-isopropylacrylamide) hydrogel microparticles (i.e. microgels) cross-linked with poly(ethylene glycol) diacrylate. These particles were grafted onto a clinically relevant polymeric material to generate conformal coatings that significantly reduced in vitro fibrinogen adsorption and primary human monocyte/macrophage adhesion and spreading. These microgel coatings also reduced leukocyte adhesion and expression of pro-inflammatory cytokines (TNF-alpha, IL-1 beta, …


Synthesis Of Multifunctional Nanogels Using A Protected Macromonomer Approach, Neetu Singh, L. Andrew Lyon Jan 2008

Synthesis Of Multifunctional Nanogels Using A Protected Macromonomer Approach, Neetu Singh, L. Andrew Lyon

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Nanoparticles possessing multiple functionalities provide synthetic handles for varied surface chemistries, making them useful for a range of applications such as biotargeting and drug delivery. However, the combination of interfering functionalities on the same particle is often challenging. We have employed a synthetic scheme involving chemical protection/deprotection to combine interfering functional groups on the same hydrogel nanoparticle. The synthesis of amine-containing poly(N-isopropylacrylamide) nanogels was carried out via free radical precipitation polymerization by incorporating a Fmoc-protected amine poly(ethylene glycol) (PEG) macromonomer. The Fmoc group was then removed to obtain free amines, which were shown to be available for conjugation. We further …


Uniform Particles Of Pure And Silica Coated Cholesterol, Vuk Uskoković, Egon Matijević Nov 2007

Uniform Particles Of Pure And Silica Coated Cholesterol, Vuk Uskoković, Egon Matijević

Pharmacy Faculty Articles and Research

Uniform crystalline colloidal cholesterol particles of narrow size distribution were obtained by precipitation. The method consisted of adding a miscible non-solvent (water) into cholesterol solutions of different alcohols and acetone, without any additives. The properties of the resulting particles depended in a sensitive way on the concentration of all reactants, temperature, pH, ionic strength, and aging time. The major observed effects were due to the solubility of cholesterol, which was strongly affected by the solvent mixture and temperature. Precipitation in 1-propanol/water system yielded stable dispersions of well-defined particles, which were used to evaluate the effects of different experimental parameters on …


Synthesis And Antifungal Properties Of Alpha-Methoxy And Alpha-Hydroxyl Substituted 4-Thiatetradecanoic Acids, Nestor Carballeira, Rosann O'Neill, Keykavous Parang Jan 2007

Synthesis And Antifungal Properties Of Alpha-Methoxy And Alpha-Hydroxyl Substituted 4-Thiatetradecanoic Acids, Nestor Carballeira, Rosann O'Neill, Keykavous Parang

Pharmacy Faculty Articles and Research

4-Thiatetradecanoic acid exhibited weak antifungal activities against Candida albicans (ATCC 60193), Cryptococcus neoformans (ATCC 6603 1), and Aspergillus niger (ATCC 16404) (MIC = 4.8-12.7 mM). It has been demonstrated that alpha-methoxylation efficiently blocks P-oxidation and significantly improve the antifungal activities of fatty acids. We examined whether antifungal activity of 4-thiatetradecanoic acid can be improved by a-substitution. The unprecedented (+/-)-2-tiydroxy-4-thiatetradecanoic acid was synthesized in four steps (20% overall yield), while the (+/-)-2-methoxy-4-thiatetradecanoic acid was synthesized in five steps (14% overall yield) starting from 1-decanethiol. The key step in the synthesis was the hydrolysis of a trimethylsilyloxynitrile. In general, the novel (+/-)-2-methoxy-4-thiatetradecanoic …


Silica-Coated Lanthanum-Strontium Manganites For Hyperthermia Treatments, Vuk Uskoković, Aljoša Košak, Miha Drofenik Sep 2006

Silica-Coated Lanthanum-Strontium Manganites For Hyperthermia Treatments, Vuk Uskoković, Aljoša Košak, Miha Drofenik

Pharmacy Faculty Articles and Research

La0.76Sr0.24MnO3 + δ particles, prepared by performing a traditional, solid-state method of synthesis, were coated by uniform layers of silica via initiating hydrolysis and condensation of TEOS in aqueous–alcoholic alkali environment. The eventually obtained samples exhibited Curie temperature at ∼40 °C, and comprised core-shell particles of ∼250 nm in diameter. By varying stoichiometric ratio of cations within manganite cores of the particles, Curie point of the resulting material can be varied too, thus opening a way for the simple design of biocompatible, temperature-self-regulating particles for application in hyperthermia treatments, with Curie point thereof adjusted to …


Rapid Determination Of Reduced And Oxidized Glutathione Levels Using A New Thiol-Masking Reagent And The Enzymatic Recycling Method: Application To The Rat Liver And Bile Samples, Imam H. Shaik, Reza Mehvar Jan 2006

Rapid Determination Of Reduced And Oxidized Glutathione Levels Using A New Thiol-Masking Reagent And The Enzymatic Recycling Method: Application To The Rat Liver And Bile Samples, Imam H. Shaik, Reza Mehvar

Pharmacy Faculty Articles and Research

A microtiter plate assay for quantitation of reduced (GSH) and oxidized (GSSG) glutathione in the rat liver tissue and bile is described. The assay is based on the established enzymatic recycling method and a new thiol-masking reagent, 1-methyl-4-vinyl-pyridinium trifluoromethane sulfonate (M4VP). Samples were first processed by homogenization with (liver) or addition of (bile) sulfosalicylic acid. The total glutathione and GSSG were then determined before and after rapid (>= 2 min) and efficient (100%) masking of the GSH content of the samples with M4VP followed by the enzymatic recycling assay. The percentages of error and coefficient of variation of the …


Linking Ligand-Induced Alterations In Androgen Receptor Structure To Differential Gene Expression: A First Step In The Rational Design Of Selective Androgen Receptor Modulators, Dmitri Kazmin, Tatiana Prytkova, C. Edgar Cook, Russell Wolfinger, Tzu-Ming Chu, David Beratan, J. D. Norris, Ching-Yi Chang, Donald P. Mcdonnell Jan 2006

Linking Ligand-Induced Alterations In Androgen Receptor Structure To Differential Gene Expression: A First Step In The Rational Design Of Selective Androgen Receptor Modulators, Dmitri Kazmin, Tatiana Prytkova, C. Edgar Cook, Russell Wolfinger, Tzu-Ming Chu, David Beratan, J. D. Norris, Ching-Yi Chang, Donald P. Mcdonnell

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We have previously identified a family of novel androgen receptor (AR) ligands that, upon binding, enable AR to adopt structures distinct from that observed in the presence of canonical agonists. In this report, we describe the use of these compounds to establish a relationship between AR structure and biological activity with a view to defining a rational approach with which to identify useful selective AR modulators. To this end, we used combinatorial peptide phage display coupled with molecular dynamic structure analysis to identify the surfaces on AR that are exposed specifically in the presence of selected AR ligands. Subsequently, we …